JP2010534908A - Street lighting equipment - Google Patents

Abstract

A street lighting arrangement for providing light distribution over an angular range between an axis and a cut-off angle, the arrangement comprising a first array (1) of at least one LED (2) having a substantially planar distribution pattern, the first array being directed at an angle intermediate to the axis and the cut-off angle, a second array of at least one LED having a substantially planar distribution pattern, the second array being directed at an angle intermediate to the axis and the cut-off angle and generally opposite to the first array, a first reflector (14) directed to receive light from the first array (1) beyond the cut-off angle and reflect it as a substantially parallel beam in the direction of the second array at close to the cut-off angle and a second reflector directed to receive light from the second array beyond the cut-off angle and reflect it as a substantially parallel beam in the direction of the first array (1) and at close to the cut-off angle.

Description

  The present invention relates to lighting devices that use light emitting diodes (LEDs), and more particularly to LED lighting devices used to illuminate public spaces such as roads and bicycle paths.

  Street lighting reflector units are designed to distribute light as uniformly as possible over the area to be illuminated with minimal visual disturbance due to glare. The optical design must meet the optimal balance of post height, light uniformity, illumination range, and light glare angle.

  Dazzle is defined as the difficulty of observation in the presence of very bright light. Dazzle is more powerful when illuminating the viewer's face in front than when bright light illuminates diagonally. In streetlights, the forward angle perceived by an observer approaching the light is known as the threshold increment (Ti). This angle is usually specified by the designer so that the light shines at an angle of at least 20 ° with the horizontal axis. One form of cut-off using a lighting device enclosure can be used to achieve this. Nevertheless, the reflection and refraction of light through the transparent cover of the lamp still dazzles and is also responsible for “light pollution”, which is upward light. The extent to which a reduction in glare is actually obtained depends largely on the effectiveness of these measures.

  A further important factor that determines glare is the perceived size of the light source or light emitting area. The amount of light emitted from a light source having a predetermined light emitting area is defined by its brightness and can be measured in units of candela per unit area. Usually, a predetermined amount of light emitted uniformly from a large area will be much less glaring than the same amount of light emitted from a small area.

Typical light sources for street lighting include incandescent lamps, fluorescent lamps and other discharge lamps. Recently, another low energy design has been developed that uses LED light sources that are densified for much higher brightness, ie flux / mm ² . This high density and high intensity, together with the monochrome characteristics of special LED light sources, requires novel methods for optical design. An additional factor in the design is the physical dimensions of the point source. As noted above, these factors are particularly important with respect to glare, since small, bright point light sources can cause glare or glare even at long distances.

  This type of known solid state light source typically uses lens optics mounted on a chip. Typically, an LED has an enclosure with an integrated lens to produce a beam having a desired aperture angle, eg, 10 ° or 70 °. Narrow beams are effective in that they increase in intensity and can be directed to the farthest point on the road. Existing designs for street lighting attempt to use a cluster of LEDs with an increased light density close to a threshold increment to achieve a uniform distribution of light on the road surface. Since the light emitting area of an LED increases with the square of the lens aperture angle, a concentrated point source using a lens or collimator cannot overcome the problem of increased glare due to excessive brightness.

  In the apparatus described in PCT patent application WO2006 / 132533, a solid state light source is provided for processing the intensity and / or direction of the generated light to illuminate a special area of the road surface. A light processing device is provided. Furthermore, the device is designed to emit light in a first wavelength region and a second wavelength region. According to that disclosure, the lighting device is designed to generate light having a dominant wavelength from the first wavelength region in a manner in which the sensitivity of the human eye is determined by the rod. Light in the second wavelength region is used to improve color perception. The use of special frequencies can improve vision at low light intensity, but the problem of glare remains.

  Therefore, there is a particular need for a lighting device that combines the advantages of a low power solid state light source with reduced glare while providing a uniform light distribution on the road surface.

  The present invention solves these problems by providing a street lighting device for providing a light distribution over an angular range between an axis and a cutoff angle, the device having at least a substantially flat distribution pattern. A first array comprising one LED and oriented at an angle between the axis and the cut-off angle; and a second array oriented at an angle between the axis and the cut-off angle and substantially opposite the first array A first array that is directed to receive light from the array and the first array that exceeds the cutoff angle and reflects the light as a substantially parallel beam toward the second array near the cutoff angle; A reflector and a second that is directed to receive light from the second array beyond a cutoff angle and reflects the light as a substantially parallel beam in the direction of the first array and near the cutoff angle; Reflection It is provided with a door. In this way, by taking light emitted beyond the cut-off angle and reflecting it at approximately the cut-off angle, the illumination at the farthest distance of the luminaire is increased without increasing the intensity of the light source Can do. Projection light close to the cut-off angle of the first array thus comes partly from the first array and partly from the second reflector. Since they are separated from each other, the effective size of the light source is also increased, thereby reducing its effective brightness.

  The following description refers to LEDs, but it should be understood that in the present invention this refers to any suitable solid state device capable of emitting light. Such a device may be a diode or other form of junction device that can efficiently convert electrical energy into light. Furthermore, a flat distribution pattern is intended to refer to a non-focal distribution of light. In particular for LEDs, this is intended to refer to the emission of light in a uniform manner close to 180 °, in particular over 120 °, preferably over a solid angle of about 140 ° or more. As will be appreciated by those skilled in the art, such a flat distribution is not completely uniform and a greater intensity is observed at an angle perpendicular to the substrate on which the LEDs are mounted compared to the angle close to the substrate surface. Can. The flat distribution is preferably realized by a spherical enclosure of LEDs. Although referring to the device housed in an enclosure, any suitable form of non-focal cover can be provided on the individual LEDs. Typically, the cut-off angle is selected at 70 ° or approximately 70 ° for most street lighting applications.

  In a preferred embodiment of the invention, each array comprises a plurality of LEDs, each LED emitting substantially monochromatic light in one of at least two different wavelength regions. Maximum energy efficiency can be achieved through the use of individual LED elements operating at a selected frequency. In particular, such LEDs have been found to last much longer and be more energy efficient than conventional broad spectrum “white” LEDs that use phosphors. Furthermore, the desired spectral distribution can be achieved by using LEDs operating at selected wavelengths.

  Most preferably, each array consists of a plurality of cyan or green LEDs emitting in the 500-525 nm wavelength region and at least one red LED emitting in the wavelength region 580-625 nm. Scientific studies have shown that this particular spectral combination gives twice as much light perception in peripheral vision.

  A typical characteristic of glare is that this is caused by the intensity and brightness of the surface of the eye and the light spots in the eye. Reflections on the wet surface of the eye interfere with vision. Refraction in the eyeball results in different blocking angles at different wavelengths. A lamp with a full spectral distribution produces various ocular occlusion angles at each different wavelength, which is known as chromatic aberration. The round shape of the eye can cause spherical aberration. These effects can be substantially reduced by reducing light intensity and by selecting a particular spectral structure of the light source. In particular, the glare can be dramatically reduced and the peripheral vision can be improved. Although light can be perceived as white light, it is actually received by different receptors in the eye. The decrease in light intensity results in what is known as twilight or “twice” vision. At these levels, rods in the eye are extremely sensitive with a peak at 507 nm at the lowest light level called dark vision. The rod is not thought to be affected by red light at all. Longer wavelength red light is received by the red sensitivity cone in the eye, allowing a sufficient degree of central vision and color contrast in street lighting requirements. In particular, note that the red sensing cone constitutes two-thirds of the total cone on the retina, and in particular, addressing these receptors is therefore effective. Both wavelengths have different blocking angles and thus form different images in the retina. Nevertheless, they are received by different receptors and are clearly processed separately by the brain. This appears to strongly reduce any perceived disturbance in vision. Furthermore, there should be no light or only minimal light in the intervening region of 525 to 580 nm. While not wishing to be bound by theory, it is believed that yellow light in this region causes rod receptor saturation and diminished mesopic vision. The ratio between the lowest visual light level known as scotopic light and the photopic level is expressed as the S / P ratio. The current ramp reaches a maximum S / P ratio of 1,5. The LED device described here can provide up to 5 S / P ratios. The double light intensity experienced at low light levels is found only at S / P ratios higher than 2.

  While the exact intensity will vary according to the particular application, it is most preferred that each array transmit less than 300 lumens of light. Depending on the exact arrangement of the lighting device, this is sufficient to illuminate the selected surface with an intensity of 1 to 3 lux. In a typical embodiment, the LEDs are made up of a matrix consisting of two rows of three cyan LEDs and one row of two red LEDs located symmetrically between the cyan LEDs. This allows for a compact spacing of the LEDs and an appropriate ratio of light in the red and cyan regions, ensuring good dimming with proper color perception. Preferably the matrix is based on a spacing of about 3.5 mm between adjacent LEDs of the same color. According to an important feature of the present invention, such a matrix should be arranged and oriented to prevent the isolated monochrome from being applied to the illuminated area. This can be achieved by aligning the different colored LEDs laterally adjacent to each other in the matrix. In this regard, the lateral direction is a direction perpendicular to the plane defined by the angular range of the light distribution.

  According to a further preferred embodiment of the invention, the reflector comprises less than 5 flat focusing surfaces aligned with each other. In this regard, the term “flat” is used to refer to a surface that is not itself intended to focus light. Nevertheless, since it is not intended to form a visible image, it contains defects and need not be optically perfectly flat. This may be glossy or matte. The term “flat focusing surface” is intended to indicate the fact that the surfaces are angled with respect to each other in an arrangement that approximates a section of a parabola with its respective array at its center. Usually, it has been found that three focusing surfaces are sufficient for most purposes. Preferably, the focusing surface can be formed integrally in a single piece. By using a flat surface in combination with light sources operating at different wavelengths, color separation can be reduced. Prior art devices have curved surface reflecting mirrors. However, this leads to drawbacks as the colors are separated in reflection by a curved surface and the resulting illumination becomes unacceptable for many purposes. It is also desirable that the dimensions of the focusing surface be limited. In particular, it has been discovered that a large surface creates an undesired movement perception as an observer passes through the illumination device. This can be overcome at least in part by limiting the size of each focusing surface to the size of its array (about 7-10 mm). The perceived image of the LED then efficiently fills the surface and no longer moves across it. It will be appreciated that the size of the focusing surface is related to its height aligned with the direction of travel along the street. The width may be larger.

  According to yet another feature of the invention, each array can be attached to a heat sink to dissipate the heat generated by the light source. The heat sink may be any suitable conductive medium, preferably a metal such as an aluminum sheet material. The LED array is preferably bonded using a thermally conductive adhesive, most preferably a UV curable acrylic adhesive.

  Most preferably, the lighting device comprises a substantially sealed housing that houses the array and the reflector. Since the service life of such LED light sources is much higher than ordinary electric lights, the housing can be permanently sealed to prevent ingress of moisture or dirt. Upon failure, the finished product is replaced or recycled. Especially for such sealed units, good heat conduction from the LED to the exterior of the housing is preferred because the lifetime of the LED is temperature dependent. This can be achieved by a suitable conduction path from the LED or heat sink to the outside. The outer surface of the housing can provide sufficient heat dissipation by natural convection. Alternatively or additionally, the heat conductor or heat pipe can be connected to a lighting support or lamp post or another heat exchange element.

  In a preferred configuration of the lighting device, the heat sink comprises a pyramid structure, and the first and second arrays are mounted back to back on opposite surfaces of the heat sink. The heat sink may be a triangular prism having two further planes that are generally aligned with the flat surfaces of the base and reflector. Such a configuration can be referred to as a 1-D illuminator because it is designed to project, for example, along the street or passage direction. In this case, the prisms and aligned reflectors can also be oriented across the street or passage direction. Alternatively, in a two-dimensional configuration, the pyramid structure can comprise three, four or more planes based on the manner in which the lighting device is deployed. Usually, the axis of the lighting device can be defined by a pyramid structure oriented in the axial direction. In this case, the surface of the heat sink is preferably angled from 60 ° to 70 ° with respect to the axis.

  In another construction, the arrays are mounted facing each other at an angle of about 60 ° to the axis and separated by a distance D. Such a configuration has a number of advantages as will be further described below. In particular, if the distance D usually corresponds to the spacing between the array and its respective reflector, the arrangement can be made more compact.

  In both structural configurations described above, the arrays can be aligned or offset laterally relative to each other. By offsetting the array in the lateral direction, a further spread of the perceived light source can be realized, leading to a reduction in its intensity. In configurations where the arrays are facing each other, the lateral offset allows for the use of more efficient reflectors.

  According to yet another feature of the invention, a base reflector is disposed between each array and its respective reflector. The base reflector is angled substantially perpendicular to the axis, i.e. facing axially. However, at least a portion of the base reflector can be angled slightly away from the axis to increase the reflection of light in the farthest range of directions. At least a portion of the base reflector can have a matte surface for acting as a diffuser. The diffuser reflects light in all directions and serves to equalize the level of illumination in the axial direction.

  According to yet another feature of the invention, the apparatus also includes a substantially transparent cap that covers the array and the reflector over at least an angular range between the axis and the cutoff angle. The transparent cap is preferably shaped to ensure that both direct and reflected light are incident at an angle of about 90 °, thereby causing internal reflection of emitted light on the interior of the transparent cover and Refraction can be reduced. In another embodiment, completely filling the optical surface of the lamp with clear polyurethane reduces the Fresnel reflection and avoids the Brewster effect that usually occurs inside a cover that is not large.

  In the above-described structure where the arrays face each other, the caps are first and second curved with a substantially planar section in between and spaced apart by a distance D existing above the first and second arrays, respectively. Sections may be provided. The first curved section can have a center of curvature located around the position of the second array and vice versa. Such devices are well adapted geometrically to ensure vertical light emission from the cap while avoiding deep profile shapes.

  In accordance with certain features of the present invention, each array can be configured to operate at less than 10 watts. In most situations, sufficient illumination up to 3 lux can be achieved with an output of less than 8 watts. Multiple arrays can be assembled in a modular configuration if increased coverage is required. In this way, the illumination coverage is increased without increasing the brightness of the light source.

  The present invention also relates to an apparatus of the type described above, further comprising a lamp post, with the array and reflector mounted on the lamp post so that the axis of the apparatus is normally vertically oriented downward, Support the array at a height of at least 3 meters above the ground.

  Further features and advantages of the present invention will be appreciated with reference to the following drawings.

FIG. 3 is a plan view of an LED array for use in the present invention. FIG. 2 is a side view of the array of FIG. It is a perspective view of the illuminating device by the 1st Embodiment of this invention. FIG. 4 is a schematic diagram of light emission from the apparatus of FIG. 3. FIG. 4 is a schematic diagram of light emission from the apparatus of FIG. 3. FIG. 4 is a schematic diagram of light emission from the apparatus of FIG. 3. FIG. 4 is a schematic diagram of light emission from the apparatus of FIG. 3. FIG. 4 is a schematic diagram of light emission from the apparatus of FIG. 3. It is sectional drawing of the 2nd Embodiment of this invention. It is a disassembled perspective view of the 3rd Embodiment of this invention. It is a perspective view of the illuminating device of FIG. 6 in the assembled state. It is a perspective view of the multi-channel illumination device by the 4th Embodiment of this invention.

  The following is given by way of example only and is a description of embodiments of the present invention with reference to the drawings. Referring to FIG. 1, an array 1 of light emitting diodes 2 mounted on a common substrate 4 is shown. The array consists of 6 cyan / green LEDs 6 and 2 amber / red LEDs 8. LEDs are otherwise normal and emit light in the wavelength bands of about 500 to 510 nm and 585 to 595, respectively. As shown in FIG. 2, the LEDs 2 are each covered with an enclosure 3 made of an epoxy resin material. Each enclosure 3 is substantially hemispherical so that light is emitted in a flat distribution pattern perpendicular to its surface and no significant refraction or focusing of the light occurs. The emitted light produces a substantially uniform cone pattern with a solid angle of about 150 °. Although not shown, it is understood that a common enclosure for all LEDs 2 can also be used.

  FIG. 3 shows a lighting device 10 according to the invention, in which a pair of arrays 1 of the type shown in FIG. 1 is attached to a heat sink 12 forming part of a reflector device 14. The housing and cap for enclosing the lighting device are not shown for reasons of clarity. The heat sink 12 has a pyramid structure in the form of a triangular prism. The vertex 16 of the heat sink 12 is aligned in the direction of the axis X of the lighting device 10. Array 1 is bonded to first surface 18 and second surface 20 of heat sink 12 using a thermally conductive adhesive.

  The reflector device 14 comprises a total of seven reflective surfaces in each array 1. For the sake of clarity, only the group of surfaces in front of face 18 will be described. However, it is understood that the surface in front of face 20 is substantially the same. Starting from the heat sink 12, the five reflective surfaces are arranged in sequence and have a base reflector 22, a base diffuser 24, a first focusing surface 26, a second focusing surface 28, and a third focusing surface 30. is doing. Side surfaces 32 and 34 are formed on the sides of the heat sink 12. The slope of the side surface will not be further described at the time, but those skilled in the art will know how to select it to meet requirements such as road width. All reflective surfaces are bright and highly reflective except for the base diffuser 24 which is a mat.

  4A-4E are cross-sectional views of the illuminating device 10 of FIG. 3 perpendicular to the apex 16 illustrating the incidence of light on different surfaces of the reflector device 14. The device 10 has been rotated upside down to the position of use and the axis X coincides with the lamp post 36. Array 1 is shown to emit light over an angle of about 140 °. In practice, the light is emitted in a conical pattern with a solid angle of about 140 °, but for the purposes of the present invention only a two-dimensional representation of the illumination pattern is considered.

  As can be seen in FIG. 4A, the surfaces 18 and 20 of the heat sink 12 are located at an angle of 25 ° away from the axis X and 50 ° to each other. This angle is selected in such a way that when mounted at a height of 4 meters above the ground, the emission of LEDs 2 from both arrays 1 has a slight overlap. When using longer lamp posts, the overlap can be greater or a smaller angle can be used instead.

  FIG. 4B shows the reflector 22 angled about 75 ° away from the axis X. Light from the array 1 incident on the base surface 22 is reflected away from the axis X and passes over the third focusing surface 30 to provide additional light at a medium distance from the lamp post 36. The base diffuser 24 is an extension of the base reflector 22 and is arranged at the same angle. The mat surface scatters incident light from the array 1 uniformly in substantially all directions. This light is mainly used to equalize the lighting effect around the base of the lamppost 36.

  FIG. 4C shows a first focusing surface 26, a second focusing surface 28, and a third focusing surface 30 located adjacent to the base diffuser 24 at a distance of about 7 cm from the heat sink 12. FIG. Each focusing surface 26, 28, 30 has a height of about 7 mm corresponding to the dimensions of the array 1. Each is angled to form a portion of a pseudo-parabolic surface that directs incident light from the array 1 with a substantially parallel beam 38. The beam 38 passes through the axis X on the heat sink 12 in the range of 60 to 70 °, providing additional illumination from the lamp post 36 to further areas under threshold increment limits.

  As shown in FIG. 4D, the surfaces 26, 28, 30 themselves are angled with respect to the axis X between 0 and 10 °. The upper end of the surface 30 is positioned so that direct light from the array passes through it at an angle between 60 ° and 70 ° with respect to the axis X. This means that the person approaching the lighting device 10 does not directly see the lowermost LED 2 until shortly before arriving at the lamp post 36.

  Based on the above dimensions, the lighting device 10 emits light, as shown in FIG. 4E, where A represents directly emitted light (about 50% of the light), and B once Represents the reflected light (about 45% of the light), and C represents the light reflected by the base diffuser (about 5% of the light). Light B is reflected with an efficiency of about 90%. About 50% of the diffused light C is lost. Overall, about 6% of the light (10% of 45% + 50% of 5%) is lost due to the absorption of the reflector. The light emitted by the lighting device is very uniform and homogeneous. It has been discovered that the generated light pattern is equal to the light distribution of a street lamp that is very compatible with the average light intensity of class 5 and 3 lux and has a uniformity greater than 0.2 (here. Uniformity is defined as the ratio of the lowest horizontal luminance to the average horizontal luminance). This is achieved with a greatly reduced power input of less than 8 watts per matrix. Based on this power rate and a lamp post with a height of 4,80 m, distances up to 12 m can be illuminated accurately. A 6m lamppost can illuminate a distance of exactly 30m with 15 watts.

  FIG. 5 shows a lighting device 110 according to a second embodiment of the present invention, wherein elements similar to the first embodiment are indicated by the same reference numerals prefixed with 100.

  According to FIG. 5, pairs of arrays 101 are mounted facing each other on a heat sink 112. The array is preferably of the type shown in FIG. 1, but it will be understood that other LED devices may be used. Array 101 is mounted in reflector device 114. A second focusing surface 128 and a third focusing surface 130 are located behind each array. The distance between the opposing focusing surfaces 128 and 130 is a distance D. It should be noted that in this embodiment, the first focusing surface is not present because it is replaced by a heat sink 112 that supports the array 101. The orientation directions of the array 101 and the reflector 114 are substantially similar to those of the embodiment of FIGS. The heat sink 112 is angled approximately 25 ° with respect to the axis X of the device 110. In other words, the normal of the surface of the heat sink 112 and the array 101 is located at an angle of 65 ° with respect to the axis X. The focusing surfaces 128, 130 reflect the light received from the array 101 as a substantially parallel beam 138 at an angle of about 70 ° with respect to the axis X. In the embodiment shown, the focusing surfaces 128, 130 are positioned immediately adjacent to the heat sink 112, so that the array 101 is therefore located at a distance D between each other. Of course, the arrays can also be positioned closer together than their respective reflective surfaces.

  A base reflector 122 is configured between the two arrays 101, usually perpendicular to the axis X. Base reflector 122 reflects a portion of the light from both arrays. In this embodiment, all surfaces of the reflector device 114 are formed from MIRO7 quality slightly matte aluminum. This material has a total reflection value of about 94% and a diffuse reflection value of 84-90% according to DIN 5036-3 and a luminance of 55-65% according to DIN 67530. As in the previous embodiment, most of the light (50%) is emitted directly. For the remaining light, about 30% is focused by the surfaces 128, 130 and directed to the tip. The remaining light is diffused almost over the area under the lamp.

  A cap 140 covering the device 110 is further shown in FIG. Cap 140 is formed from a clear polycarbonate and includes a pair of curved ends 142 separated by a substantially flat central section 144. The flat central section 144 extends over the focusing surfaces 128, 130 and the array 101 and is therefore greater than the distance D. Curved surface 142 provides a section of cap 140 through which beam 138 can pass with little refraction. The remaining light from each array 101 passes primarily through the flat central section 144 and is therefore relatively unaffected by the separation of different wavelengths.

  FIG. 6 shows a lighting device 210 according to a third embodiment of the present invention, wherein elements similar to the first embodiment are indicated by the same reference numerals prefixed with 200.

  The third embodiment is typically similar to the structure of FIG. 5 in that the illumination device 210 is between a first and second channel 246 and 248 having two partial reflector devices 214, 214 ′. It is divided horizontally. The reflector devices 214, 214 'are also manufactured using MIRO7 quality aluminum. The first array 201 is supported on a heat sink 212 located in the first channel 246. Located on opposite ends of the first channel 246 are a first focusing surface 226, a second focusing surface 228, and a third focusing surface 230 that are not seen in this view. Located in the second channel 248 adjacent to the focusing surfaces 226, 228, 230 is a second array 201 'that is not seen in this drawing but is substantially the same as the first array 201. Facing the second array 201 ′ at the opposite end of the second channel 246 is the first focusing surface 226 ′, the second focusing surface 228 ′, the third of the second reflector device 214 ′. A focusing surface 230 '. Each partial reflector device 214, 214 'also has a base reflector 222, 222', lateral surfaces 232, 232 'and 234, 234'. Note that the transverse surfaces 232, 232 'are generally perpendicular (parallel to the axis X) and the transverse surfaces 234, 234' are angled at about 45 ° to the axis. Such lighting devices are designed to be located on one side of a street or aisle, and the angled lateral surfaces 234, 234 'allow light to be projected across the street width to the side streets Enable.

  Also shown in FIG. 6 is a cap 240 and a housing 250 that cover the lighting device 210, and the housing 250 together with the cap 240 forms an efficiently sealed unit. Cap 240 is a low profile structure as described with respect to FIG. 5 and includes curved ends 242 separated by a substantially flat central section 244. The housing 250 is formed from cast aluminum and has a recess 252 that receives the reflector devices 214, 214 '. Located in the recess 252 is a heat pipe 254 configured to act as a heat conduction path from the arrays 201, 201 'to the outside of the housing. The heat pipe 254 also acts as a conduit for electrical connection to the arrays 201, 201 'and connection to the external support or lamp post of the lighting device 210.

  FIG. 7 further shows the assembled lighting device 210 when viewed in the direction of threshold increment or cut-off angle according to arrow V in FIG. At this angle, the first array 201 is not directly visible, but appears to be reflected at each focusing surface 226, 228, 230. The array 201 ′ is seen in the second channel 248. Further, as seen in this orientation, the view of array 201 ′ and the reflected image of array 201 occur through end 242 of cap 240.

  Further, assuming the LED device schematically shown in FIG. 1 in FIG. 7, the orientation of the array 201, 201 ′ with respect to the reflector device 214, 214 ′ is the angle of light distribution between the multiple cyan LEDs and the red LEDs. They are adjacent to each other in a direction perpendicular to the plane defined by the range. Such a configuration prevents an isolated single color from being applied to the illuminated area.

  FIG. 8 shows a perspective view of a fourth embodiment of a multi-channel lighting device 310 similar to that of FIGS. Elements similar to the first embodiment are indicated by the same reference numerals prefixed with 300.

  According to FIG. 8, the lighting device 310 is the same as that of FIG. 6 except that it comprises two sets of first and second channels 346 and 348. Cap 340 and housing 350 together form a sealed unit. The housing 350 is formed from cast aluminum and has a recess 352 for receiving the reflector device 314. Bracket 356 allows connection of lighting device 310 to an external support or lamp post 336.

  The invention has been described with reference to the preferred embodiments as described above. It will be appreciated that these embodiments are capable of various modifications and alternative forms well known to those skilled in the art. For example, the reflectors can be performed in a modular manner and positioned in cascade with additional arrays for higher strength and / or higher masts. In particular, the reflector devices of FIGS. 6, 7, and 8 can be formed with additional channels depending on the desired illumination output. In FIG. 3, the prism-shaped heat sink can be expanded for yet another array position. Alternatively, instead of a prism, a three-sided or four-sided pyramid can be used for wider area illumination.

  In addition to the foregoing, numerous other modifications can be made to the structures and techniques described herein without departing from the scope of the invention. Accordingly, although specific embodiments have been described, these are merely exemplary and are not intended to limit the technical scope of the present invention.

Claims (22)

In a street lighting device that gives a light distribution over an angular range between the axis and the cut-off angle,
A first array comprising at least one LED having a substantially flat distribution pattern and oriented in an angular direction intermediate between an axis and a cutoff angle;
A second array comprising at least one LED having a substantially flat distribution pattern, oriented in an angular direction intermediate between the axis and the cut-off angle, and substantially opposite the first array;
A first light beam directed to receive light from the first array that exceeds the cut-off angle and reflects the light at a cut-off angle in the direction of the second array as a substantially parallel beam in the direction of the second array. 1 reflector,
A second reflector that is directed to receive light from a second array that exceeds a cutoff angle and reflects the light at a cutoff angle as a substantially parallel beam in the direction of the first array. Equipment.   The apparatus of claim 1, wherein each array comprises a plurality of LEDs, each LED emitting substantially monochrome light in one of at least two different wavelength regions.   3. The apparatus of claim 2, wherein each array comprises a plurality of cyan LEDs that emit in the wavelength region of 500-525 nm and at least one red LED that emits in the wavelength region of 580-625 nm.   4. The apparatus of claim 3, wherein the plurality of cyan LEDs and the at least one red LED are arranged adjacent to each other in a direction perpendicular to a plane defined by the angular range of the light distribution.   5. An apparatus according to any one of the preceding claims, wherein each reflector comprises no more than four flat focusing surfaces aligned with each other.   6. An apparatus according to any one of the preceding claims, wherein the arrays are mounted back to back at an angle of about 60 [deg.] With respect to the axis.   7. An apparatus according to any one of the preceding claims, wherein the arrays are mounted at a distance D facing each other at an angle of about 60 DEG to the axis.   8. An apparatus according to claim 6 or 7, wherein the arrays are offset laterally with respect to each other.   9. The method of claim 1, further comprising first and second base reflectors disposed between each array and its respective reflector and substantially perpendicular to the axis. Equipment.   The apparatus of claim 9, wherein at least a portion of the first or second base reflector comprises a matte surface configured to reflect light to diffuse.   11. A device according to any one of the preceding claims, wherein the cut-off angle is about 70 ° with respect to the axis.   12. An apparatus according to any preceding claim, wherein each array is mounted on a heat sink.   13. Apparatus according to any one of the preceding claims, further comprising a substantially sealed housing enclosing the array and reflector.   14. The apparatus of claim 13, wherein each array is provided with a heat transfer path to the exterior of the housing.   The apparatus of claim 14, wherein the heat transfer path comprises a heat pipe.   16. A method according to any one of the preceding claims, further comprising a substantially transparent cap that covers the array and reflector over at least an angular range between the axis and the cutoff angle.   The apparatus of claim 16 wherein the cap is filled with a substantially solid transparent material.   The apparatus further comprises a substantially transparent cap covering the array and the reflector, the cap comprising first and second curved sections separated by a substantially flat section having a length greater than D. The apparatus of claim 16, wherein the first section is located above the array and the reflector.   19. An apparatus according to any preceding claim, wherein each array is configured to operate at less than 10 watts.   20. Apparatus according to any one of the preceding claims, wherein each array has an s / p ratio greater than 2.0.   The lamp post is further equipped with an array and reflector mounted on the lamp post so that the axis of the device is oriented substantially vertically downward, and the lamp post supports the array at a height of at least 3 meters above the ground. 21. Apparatus according to any one of claims 1 to 20.   The apparatus of claim 21, wherein the lamp post comprises a plurality of arrays and reflectors mounted together in parallel.

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